Specify Epoch TimeDate Format when serializing/deserializing with Utf8Json

Question

i couldn't find enough informations about howto handle DateTimeOffset and TimeSpan during serializing and deserializing with utf8json. i could find Infos about the IJsonFormatter, but not howto implement it correctly..

My example Class looks like this:

public MyClass()
{
 // This should be converted during serializing/deserializing  to Unix TimeStamp in Milliseconds  
  [JsonFormatter(typeof[CustomDateTimeConverter())]  
  public DateTimeOffSet? BeginDate { get; set; }

  // This should be converted to TotalMilliseconds
  public TimeSpan? Elapsed { get; set; } 
}

I have a function to convert the Datetime to EpochTimeStamp from this post: How to get the unix timestamp in C#

I tried to add [JsonFormatter(typeof[CustomDateTimeConverter())] to the datamember BeginDate, but need to implement it correctly..

public class CustomDateTimeConverter : IJsonFormatter
{
    public CustomDateTimeConverter()
    {
       // convert DateTime to Unix Milliseconds for Serialzing
    }
}

Or i am on the wrong way ? How can i achieve this ?

Thank you, for helping !

Answer 1

my solution expands my class without the use of IJsonFormatter. The Class now looks like this:

public MyClass()
{

  [IgnoreDataMember]
  // This field will be used internally
  public DateTimeOffSet? BeginDate { get; set; }


  [DataMember(Name = "beginDate")]
  // This will be used for serialzing/deserialising to Unix TimeStamp in Milliseconds 
  public long BeginDateEpoch
  {
    get { return ((DateTimeOffset)BeginDate.GetValueOrDefault()).ToUnixTimeMilliseconds(); }
    set { BeginDate= new DateTimeOffset(DateTimeOffset.FromUnixTimeMilliseconds(value).DateTime.ToLocalTime()); }
  }

  [IgnoreDataMember]
  public TimeSpan? Elapsed { get; set; } 

  [DataMember(Name = "elapsed")]
  public double ElapsedEpoch
  {
    get { return Elapsed.GetValueOrDefault().TotalMilliseconds;  }
    set { Elapsed = TimeSpan.FromMilliseconds(value); }
  }

}